Prognostic Factors of Facial and Tongue Functional Outcomes Following Side-to-End Hypoglossal-Facial Nerve Transfer: A 20-Year Multidisciplinary Experience.

Introduction

Side-to-end hypoglossal-facial nerve transfer (HFT) is an established facial reanimation technique. However, evidence regarding predictors of outcomes is limited.

Objective

To evaluate predictors of facial and tongue outcomes after HFT in a large series of patients with facial palsy.

Methods

A retrospective review of 64 patients undergoing side-to-end HFT was conducted. Additional masseteric nerve transfer and/or cross-facial nerve grafting were performed in selected cases. Facial outcomes were evaluated with the House-Brackmann (HB) scale, the Sunnybrook Facial Grading System, and eFACE. Tongue outcomes were assessed using Martin's scale and Oral and Pharyngeal Disability Index. Multivariate regression analyses identified independent associations.

Results

HB grade III or IV was achieved in 95.3% of patients. Significant improvements were observed in all facial function scales (p < 0.001). Tongue function was preserved in 98.4%. Patient-reported scores indicated good perceived oral-pharyngeal outcomes (79.3, interquartile range = 67.9-87.4). Higher age predicted poorer facial (β = -0.303, p = 0.009) and tongue (β = -0.371, p = 0.006) outcomes. Delayed recovery onset correlated with worse facial results (β = -0.389, p = 0.001). Double nerve reinnervation was associated with better facial outcomes (p = 0.007).

Conclusions

This technique offers effective facial reanimation with minimal tongue morbidity. Older age and delayed recovery onset were associated with poorer outcomes, supporting tailored surgical strategies.